code: def push(image: str, tag: str) -> Optional[str]:
      """Push an image to a remote registry."""
      return shell(["push", f"{image}:{tag}"])
  
imports: import json
  import logging
  import os
  import subprocess
  from typing import Any, Dict, List, Optional, Tuple, Union
  import requests
  from dockerpycreds.utils import find_executable
  from wandb.docker import auth, www_authenticate
  from wandb.errors import Error
label_desc: Use image node_id 16 for calling a global function with example usage: push(image, tag) and returns: shell